Your vibrationdata post is a great source of information.
If you don’t mind, I have a silly question about the random vibration.
When a structure is random vibration tested, the test random spec (PSD) is 1-sigma level but for the random vibration analysis of the same structure, the same spec is applied and 3-sigma stress is used to check the structure margin. Does this mean random vibration 1-sigma test is equivalent to 3-sigma analysis?
I’d appreciate if you can share your thoughts on this.